Step 1

Preheat oven to 160°C/325°F. Grease two deep 15cm (6-inch) round cake pans; line bases and sides with two layers of baking paper.

Step 2

Stir white chocolate, butter, sugar, milk and vanilla in a medium saucepan over medium heat until smooth. Transfer to a large heatproof bowl; cool slightly. Stir in eggs, then stir in sifted flours. Pour mixture evenly into pans.

Step 3

Bake cakes for 50 minutes or until a skewer inserted into the centre comes out clean. Leave cakes in pans for 5 minutes before turning, top-side up, onto a wire rack to cool.

Step 4

Meanwhile, make malted buttercream; heat milk in a small saucepan until warm; stir in malted milk powder to form a smooth paste. Chill in the fridge for 10 minutes. Beat butter and icing sugar in a small bowl with an electric mixer until light and fluffy. Add malted milk powder mixture; beat well until light and fluffy.

Step 5

Trim tops from cakes to level; split cakes in half. Place one cake layer on a plate or stand. Reserve half the malted buttercream for final coating on top and side of cake. Spread cake layer with a little of the remaining buttercream to create a thin layer. Top with another layer of cake. Repeat layering using remaining portion of buttercream and remaining cake layers, leaving enough buttercream to spread a very thin layer or 'undercoat' over top and side of cake. Refrigerate for 30 minutes.

Step 6

Spread reserved buttercream smoothly over top and side of cake, for final coating. Press combined biscuits and peanuts around bottom third of cake. Refrigerate for 30 minutes or until firm.

Step 7

Meanwhile, make ganache; stir ingredients in a small saucepan over low heat until smooth. Cool ganache for 10 minutes or until it resembles thickened cream.

Step 8

Pour cooled ganache over top of cake, allowing mixture to run down side. Stand until set.

Step 9

Using a clean small, soft brush, dust chocolates lightly all over with gold and silver lustre powder. Arrange chocolates on cake, securing with a little extra ganache, if needed. Dust with a little more gold and silver lustre powder, if you like.